A series variable stiffness decoupled suspension, stiffness matching method, damping matching method and adjustment method

Abstract

This invention belongs to the field of variable stiffness decoupled suspension technology, specifically relating to a series variable stiffness decoupled suspension, stiffness matching method, damping matching method, and adjustment method. It includes a pair of damping brackets, each comprising a vertical torsion bar spring. A rotating sleeve is fitted at the bottom of the vertical torsion bar spring, and the rotating sleeve has a first swing arm, a second swing arm, a third swing arm, and a fourth swing arm. A tie rod is hinged to the end of the first swing arm, and a control arm is hinged to the other end of the tie rod. A steering tie rod is hinged to the control arm. A connecting rod is hinged to the front of the second swing arm, and a transverse torsion bar spring is hinged to the connecting rod of the two damping brackets. A transverse magnetorheological damper is hinged between the third swing arms of the two damping brackets. A longitudinal barrel-type magnetorheological damper is hinged to the end of the fourth swing arm. A spring support structure is hinged to the top of the vertical torsion bar spring, enabling it to adapt to different operating conditions and improving the ride comfort and handling of the vehicle in curves and at high speeds.

Description

Technical Field

[0001] This invention belongs to the field of variable stiffness decoupling suspension technology, specifically relating to a series variable stiffness decoupling suspension, a stiffness matching method, a damping matching method, and an adjustment method. Background Technology

[0002] For small passenger vehicles, the chassis often uses passive suspension matched with the body. In this case, the chassis setting of the whole vehicle is biased towards neutrality, meaning that the ride comfort and handling stability of the whole vehicle cannot reach the best state. The chassis characteristics of the vehicle are singular and unadjustable, and it is impossible to achieve decoupling between smoothness and handling. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a series variable stiffness decoupled suspension, which gives the vehicle chassis multiple stiffness characteristics, enabling it to adapt to different operating conditions and improving the ride comfort and handling of the vehicle in curves and at high speeds.

[0004] The technical solution of the present invention is as follows:

[0005] A series variable stiffness decoupled suspension includes a pair of damping brackets. Each damping bracket includes a vertical torsion bar spring. The vertical torsion bar spring is hinged to the chassis of the vehicle via a deep groove ball bearing. A rotating sleeve is sleeved at the bottom end of the vertical torsion bar spring. A first swing arm, a second swing arm, a third swing arm, and a fourth swing arm extend outward from the upper end of the rotating sleeve.

[0006] A tie rod is hinged to the end of the first swing arm, and a control arm is hinged to the other end of the tie rod. A steering tie rod is hinged to the control arm.

[0007] The second swing arm has a connecting rod hinged to the front side. One end of a transverse torsion bar spring is hinged to the connecting rod of one shock absorber bracket, and the other end of the connecting rod of the other shock absorber bracket is hinged to the other end of the transverse torsion bar spring.

[0008] A transverse magnetorheological damper is hinged between the shock-absorbing supports, and the two ends of the transverse magnetorheological damper are respectively hinged to the third swing arm of the two shock-absorbing supports.

[0009] The fourth swing arm is hinged to a longitudinal barrel-type magnetorheological damper at its end.

[0010] The top of the vertical torsion bar spring is hinged with a spring support structure.

[0011] Preferably, the spring support structure includes a rotary electromagnetic clutch hinged to the top of a vertical torsion bar spring, a rotary sleeve is fitted on the outer shell of the rotary electromagnetic clutch, a fifth swing arm extends outward from the rotary sleeve, and a helical spring is hinged to the end of the fifth swing arm.

[0012] The control arm has an upper control arm and a lower control arm. The tie rod is hinged to the upper control arm. The upper control arm and the lower control arm are both a pair of horizontal arms and are fixed to a steering knuckle. The pair of horizontal arms are A-shaped. The steering tie rod is hinged to the steering knuckle. The steering knuckle is connected to the wheel.

[0013] A stiffness matching method for a series variable stiffness decoupled suspension, wherein the series variable stiffness decoupled suspension has a suspension force transmission model, and the spring stiffness algorithm of the series variable stiffness decoupled suspension under static load equilibrium is obtained based on the suspension force transmission model, and the spring stiffness under static load equilibrium condition is obtained based on the spring stiffness algorithm.

[0014] Preferably, the spring stiffness algorithm is as follows:

[0015]

[0016] Where K is the spring stiffness; x is the spring installation stroke; g is the gravitational acceleration; a is the angle between the steering kingpin and the XZ plane; d is the angle between the upper control arm and the XY plane; n is the angle between the spatial force Fc' and the XY plane; m is the angle between the projected component force Fd and the X-axis; e is the angle between the helical spring and the fifth swing arm; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; ad L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de For the spatial lever arm of the longitudinal magnetorheological damper; L ef L is the spatial lever arm of the transverse magnetorheological damper; fg M is the spatial lever arm of the helical spring; M is one-quarter of the vehicle body mass.

[0017] A damping matching method for a series variable stiffness decoupled suspension, wherein the series variable stiffness decoupled suspension has a suspension force transmission model, a viscous damping coefficient formula is obtained based on the suspension force transmission model, a viscous damping coefficient is obtained based on the viscous damping coefficient formula, and parameters of the series variable stiffness decoupled suspension are obtained based on the viscous damping coefficient.

[0018] Preferably, the formula for the viscous damping coefficient is as follows:

[0019]

[0020] A = L ac +L ad

[0021] B = L de 2 sinf+L ef 2 sing

[0022] in, This is the acceleration of the vehicle body in the Z-axis direction; M1 is the velocity of the vehicle body in the Z-axis direction; M1 is the mass of the vertical torsion bar spring; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; ad L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de For the spatial lever arm of the longitudinal magnetorheological damper; L ef L is the spatial lever arm of the transverse magnetorheological damper; fg F is the spatial lever arm of a helical spring. m denoted as _f_, where _f is the angle between the longitudinal magnetorheological damper and the fourth swing arm; _n_, where _n_ is the angle between the spatial force Fc' and the XY plane; _m_, where _m_ is the angle between the projected component force Fd and the X-axis; _g_, where _g_ is the angle between the transverse magnetorheological damper and the third swing arm; _e_, where _e_ is the angle between the helical spring and the fifth swing arm; and _M_, where M is one-quarter of the vehicle body mass.

[0023] A method for adjusting a series variable stiffness decoupled suspension, wherein a speed sensor, a vertical acceleration sensor, and a pitch rate sensor are installed inside the vehicle body, and the adjustment method includes the following steps:

[0024] Step S1: Determine the road conditions based on the vehicle's longitudinal speed and vertical acceleration, and determine the vehicle's operating status based on the pitch angular velocity;

[0025] Step S2: Power on or off the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper according to different road conditions and vehicle operating status.

[0026] Step S3: Based on the energization or de-energization status of the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper, the working state of the transverse barrel magnetorheological damper, the longitudinal barrel magnetorheological damper, the transverse torsion bar spring, the vertical torsion bar spring, the steering tie rod, and the helical spring is adjusted using a neural fuzzy parallel fusion algorithm.

[0027] Furthermore, step 1 is further specified as follows:

[0028] Step S11: When the vehicle speed is greater than 40 km / h or the vertical acceleration of the vehicle body is less than 0.4 m / s² 2 The road conditions were deemed good.

[0029] Step S12: When the vehicle speed is less than 40 km / h or the road surface condition is good, the vertical acceleration of the vehicle body is greater than 0.7 m / s². 2 The road conditions were deemed poor.

[0030] Step S13: When the vehicle body pitch angle is greater than 200 deg / s 2 This determines that the vehicle is in a state of rapid acceleration or braking.

[0031] Step S14: When the vehicle body roll angle acceleration is greater than 45 deg / s 2 At that time, it was determined that the vehicle was turning at high speed.

[0032] Furthermore, step 2 is further specified as follows:

[0033] Step S21: When the road conditions are good, adjust the vehicle handling by energizing the rotary electromagnetic clutch, energizing the longitudinal barrel magnetorheological damper, and de-energizing the transverse barrel magnetorheological damper.

[0034] Step S22: When the road conditions are poor, adjust the vehicle ride comfort, de-energize the rotary electromagnetic clutch, energize the longitudinal barrel magnetorheological damper, and de-energize the transverse barrel magnetorheological damper.

[0035] Step S23: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized.

[0036] Step S24: When the vehicle is cornering at high speed, the current of the transverse barrel magnetorheological damper is cut off.

[0037] Furthermore, step 3 specifically involves: using a neural network algorithm model to identify the suspension. Input parameters include: road conditions, error, damping force of the lateral barrel magnetorheological damper, and damping force of the longitudinal barrel magnetorheological damper. The output parameters of the identified structure are the vehicle's vertical acceleration, vehicle pitch acceleration, and vehicle roll acceleration. These output parameters are used to control the damping forces of the lateral and longitudinal barrel magnetorheological dampers in real time. The neural network algorithm model is as follows:

[0038]

[0039] y p (k+1) and y m (k+1) represents the output value of the suspension physical model and the neural network prediction model at time k+1; u(k) represents the input value of the suspension physical model and the neural network prediction model at time k, n represents the nth time, and m represents the mth time;

[0040] Step S31: The rotary electromagnetic clutch is de-energized, the longitudinal barrel magnetorheological damper is energized, the transverse barrel magnetorheological damper is de-energized, the helical spring works, the longitudinal barrel magnetorheological damper works actively, and the torsion bar spring does not work.

[0041] Step S32: The rotary electromagnetic clutch is energized, the longitudinal barrel magnetorheological damper is energized, the transverse barrel magnetorheological damper is de-energized, the vertical torsion bar spring is working, the longitudinal barrel magnetorheological damper is working, and the transverse torsion bar spring and helical spring are not working.

[0042] Step S33: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized and the transverse barrel magnetorheological damper works.

[0043] Step S34: When the vehicle is cornering at high speed, the current of the lateral barrel magnetorheological damper is cut off, the lateral torsion bar spring is activated, and the lateral barrel magnetorheological damper is passively activated.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] This invention starts with the structure of the suspension and the geometry of the linkage, and changes the working characteristics of the suspension according to different driving conditions, thereby realizing different characteristics of the whole vehicle chassis and achieving decoupling between ride comfort and handling.

[0046] Coil springs and vertical torsion bar springs are two types of springs with different characteristics. Coil springs generally have low stiffness and a large stroke range, making them suitable for smooth driving conditions. Vertical torsion bar springs generally have high stiffness, small torsional stroke, and high toughness (with shock absorber characteristics), making them suitable for handling conditions such as cornering and high speed.

[0047] By combining the characteristics of two different springs and considering the setting of the force transmission system, the force transmission system can be automatically switched to different springs according to different operating conditions of the vehicle. This allows the same vehicle model to have two or even more chassis characteristics with different stiffnesses, perfectly decoupling the handling conditions such as "nose-up" during start-up acceleration, "nose-down" during braking, cornering, and high-speed operation from the smoothness conditions. Attached Figure Description

[0048] Figure 1 This is a schematic diagram of the suspension structure;

[0049] Figure 2 This is a structural schematic diagram of the suspension from another perspective;

[0050] Figure 3 This is a structural schematic diagram of the entire vehicle;

[0051] Figure 4 A schematic diagram of the suspension force transmission model in this invention;

[0052] Figure 5 This is a schematic diagram of the push rod spatial force transmission in this invention;

[0053] Figure 6 A schematic diagram illustrating front suspension damping matching under different accelerations;

[0054] Figure 7 A schematic diagram illustrating the matching of rear suspension damping under different accelerations;

[0055] Figure 8 This is a flowchart of the adjustment method of the present invention;

[0056] Figure 9 This is a framework diagram of the neural fuzzy parallel fusion algorithm of the present invention;

[0057] In the diagram: 1-Pull rod, 2-Rotating sleeve, 3-First swing arm, 4-Vertical torsion bar spring, 5-Longitudinal barrel magnetorheological damper, 6-Rotary electromagnetic clutch, 7-Fifth swing arm, 8-Helical spring, 9-Control arm, 91-Upper control arm, 92-Lower control arm, 10-Steering tie rod, 11-Second swing arm, 12-Third swing arm, 13-Transverse torsion bar spring, 14-Transverse magnetorheological damper, 15-Fourth swing arm. Detailed Implementation

[0058] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0059] See Figure 1-2 A series variable stiffness decoupled suspension includes a pair of damping brackets. The damping bracket includes a vertical torsion bar spring 4. The vertical torsion bar spring 4 is hinged to the chassis of the vehicle through a deep groove ball bearing. A rotating sleeve 2 is sleeved at the bottom end of the vertical torsion bar spring 4. A first swing arm 3, a second swing arm 11, a third swing arm 12 and a fourth swing arm 15 extend outward from the upper end of the rotating sleeve 2.

[0060] Please see Figure 1-3 The first swing arm 3 is hinged to a tie rod 1 at one end, and a control arm 9 is hinged to the other end of the tie rod 1. The tie rod is outside the upper and lower control arms, and its spatial position can be changed according to the layout of the vehicle chassis to facilitate the installation of other systems (engine, electric motor and other power sources or auxiliary components).

[0061] See Figure 3 The control arm 9 is hinged with a steering tie rod 10, which is connected to the vehicle's steering wheel.

[0062] The second swing arm 11 has a connecting rod hinged to its front side. One end of a transverse torsion bar spring 13 is hinged to the connecting rod of one shock absorber bracket, and the other end of the connecting rod of the other shock absorber bracket is hinged to the other end of the transverse torsion bar spring 13.

[0063] A transverse magnetorheological damper 14 is hinged between the shock-absorbing brackets. The two ends of the transverse magnetorheological damper 14 are respectively hinged to the third swing arm 12 of the two shock-absorbing brackets. The transverse magnetorheological damper 14 can limit the rotation angle of the rotating sleeve 2 and thus limit the vibration of the vehicle body.

[0064] The fourth swing arm 15 is hinged to a longitudinal barrel-type magnetorheological damper 5 at its end.

[0065] The top of the vertical torsion bar spring 4 is hinged with a spring support structure.

[0066] See Figure 1-2 The spring support structure includes a rotary electromagnetic clutch 6 hinged to the top of the vertical torsion bar spring 4. A rotary sleeve is fitted on the outer shell of the rotary electromagnetic clutch 6. A fifth swing arm 7 extends outward from the rotary sleeve. A helical spring 8 is hinged to the end of the fifth swing arm 7.

[0067] Please continue reading Figure 1-2 The control arm 9 has an upper control arm 91 and a lower control arm 92. The tie rod 1 is hinged to the upper control arm 91. The upper control arm 91 and the lower control arm 92 are both a pair of horizontal arms, which are A-shaped. The upper control arm 91 and the lower control arm 92 are fixedly connected by a steering knuckle. The steering tie rod 10 is hinged to the steering knuckle, and the steering knuckle is connected to the wheel.

[0068] During work, the work situation is divided into the following categories:

[0069] Smoothness of operation: When the rotary electromagnetic clutch 6 is de-energized, the up-and-down movement of the wheels drives the tie rod assembly 1 through the upper control arm 91. The tie rod assembly drives the lower end rotating sleeve 2 of the torsion bar spring to rotate (the vertical torsion bar spring 4 is fixed on the lower end rotating sleeve 2 and the upper end rotating sleeve, and the upper end rotating sleeve is fixed on the outer shell of the rotary electromagnetic clutch 6). The lower end rotating sleeve 2 drives the helical spring to work through the vertical torsion bar spring (the stiffness of the vertical torsion bar spring is much greater than that of the coil spring, and at this time the deformation of the vertical torsion bar spring is very small, which is equivalent to a rigid body). The upper end rotating sleeve then drives the coil spring to work. The overall vehicle smoothness is good.

[0070] Handling condition: When the rotary electromagnetic clutch 6 is energized, it locks the longitudinal torsion bar spring to the frame. The up-and-down movement of the wheels drives the pull rod 1 through the upper control arm 91. The pull rod 1 drives the rotating sleeve 2 at the lower end of the vertical torsion bar spring 4 to rotate. The lower rotating sleeve 2 drives the vertical torsion bar spring 4 to rotate (the upper end is locked, and the coil spring does not work); the overall vehicle handling is good.

[0071] Acceleration or braking: When a vehicle accelerates or brakes rapidly, the vehicle pitch angle will increase (pitch acceleration greater than 200 deg / s). 2At this time, the current of the transverse magnetorheological damper 14 increases, the damping force increases, and the pitch angle of the vehicle body decreases. The left and right vehicles jump up or down at the same time. The upper control arm drives the rotating sleeve 2 to rotate through the pull rod. The third swing arm on the rotating sleeve will limit the rotation angle of the third swing arm under the action of the transverse magnetorheological damper 14. This will suppress the amplitude of the vehicle's vertical jump in the opposite direction. The amplitude of the vehicle's vertical jump is reduced, the pitch angle of the vehicle body is reduced, and the stability of the whole vehicle is improved.

[0072] Cornering conditions: When a vehicle is cornering at high speed, the body roll angle will increase (roll acceleration greater than 45 degrees / s). 2 When the current of the transverse magnetorheological damper 14 decreases or is de-energized, the transverse torsion bar spring 13 links the left and right wheels to reduce the body roll angle and improve stability.

[0073] In one embodiment of the present invention, a stiffness matching method for a series variable stiffness decoupled suspension is provided. The method comprises: the series variable stiffness decoupled suspension has a suspension force transmission model; obtaining a spring stiffness algorithm for the series variable stiffness decoupled suspension under static load equilibrium based on the suspension force transmission model; obtaining the spring stiffness under static load equilibrium based on the spring stiffness algorithm; and matching the suspension size based on the spring stiffness.

[0074] Series variable stiffness decoupled suspension force transmission model as follows Figure 4 As shown, the force transmitted by the push rod in space is as follows: Figure 5 As shown;

[0075] The force transmission of a series variable stiffness decoupled suspension is described as follows:

[0076] F o =Mg (1)

[0077] F o =F a cos a (2)

[0078] F b L ad cos d=F a cos a(L ac +L ad cos d (3)

[0079] F c sin n = F b (4)

[0080] F c =-F c' (5)

[0081] F c' cosn=F d (6)

[0082] F d cos m=F e (7)

[0083] F e L be =F g L de sin f+F n L ef sin g+F m L fg sin e (8)

[0084] F m =Kx (9)

[0085] F g =βv1 (10)

[0086] F n =βv2 (11)

[0087] When the vehicle is stationary, the force generated is 0. Substituting formulas (1)-(7) and (9)-(11) into formula (8) and rearranging, we get formula (12):

[0088]

[0089] Among them, F o F is the reaction force of the ground on the wheel. a The thrust that pushes the control arm onto the steering knuckle; F c Fc' is the spatial tension of the lever on the upper control arm; Fc' is the spatial tension of the lever on the first swing arm; F b For spatial force F c The component of the force in the vertical direction (Z-axis direction); F d For spatial force F c' The projected component of the force on the XY plane; F e For F d Projected component of force on the X-axis; F m F is the spring force. g For longitudinal damping force; F n β is the lateral damping force; K is the spring stiffness; x is the spring installation stroke; β is the viscous damping coefficient; g is the gravitational acceleration; a is the angle between the steering kingpin and the XZ plane; d is the angle between the upper control arm and the XY plane; n is the angle between the spatial force Fc' and the XY plane; m is the angle between the projected component force Fd and the X-axis; g is the angle between the lateral magnetorheological damper and the third swing arm; e is the angle between the helical spring and the fifth swing arm; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; adL is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de For the spatial lever arm of the longitudinal magnetorheological damper; L ef L is the spatial lever arm of the transverse magnetorheological damper; fg M is the spatial lever arm of the helical spring; M is one-quarter of the vehicle body mass.

[0090] During an experiment, the parameters of the series variable stiffness decoupled suspension are shown in Table 1.

[0091]

[0092] According to formula (12), the spring force under static load balance is calculated to be -830.95N. The negative sign indicates that the spring is in a stretched state. In reality, the suspension will change the spring to a compressed state by reversing the arrangement of the front and rear ends of the spring. The spring installation stroke is 70 mm, and the actual compression stroke is less than 70 mm (due to the diameter of the coil spring). The compression stroke is selected as 40 mm. At this time, the spring stiffness is calculated to be 20.8 N / mm. Assuming that the maximum vertical acceleration of the vehicle body in the operating condition is 1g, after comprehensive consideration, the front suspension is selected as 45 N / mm; the rear suspension is selected as 50 N / mm.

[0093] In another embodiment of the present invention, a damping matching method for a series variable stiffness decoupled suspension is provided, wherein the series variable stiffness decoupled suspension has a suspension force transmission model, a viscous damping coefficient formula is obtained based on the suspension force transmission model, a viscous damping coefficient is obtained based on the viscous damping coefficient formula, and parameters of the series variable stiffness decoupled suspension are obtained based on the viscous damping coefficient.

[0094] When the vehicle is in equilibrium, it experiences a momentary vertical acceleration. At this moment, the shock absorbers activate, and the vehicle body generates inertial force under the action of vertical acceleration. The force transmission model of the suspension is described as follows:

[0095]

[0096] M1L be 2 α=F e L be (14)

[0097] v=∫L be αdt (15)

[0098]

[0099]

[0100]

[0101] A = L ac +L ad (19)

[0102] B = L de 2 sin f+L ef 2 sin g (20)

[0103] in, This is the acceleration of the vehicle body in the Z-axis direction; α is the velocity of the vehicle body in the Z-axis direction; v is the tangential velocity at the connection between the tie rod and the first swing arm; v1 is the tangential velocity at the connection between the longitudinal magnetorheological damper and the fourth swing arm; v2 is the tangential velocity at the connection between the transverse magnetorheological damper and the third swing arm; α is the angular acceleration of the vertical torsion bar spring; M1 is the mass of the vertical torsion bar spring; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; ad L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de For the spatial lever arm of the longitudinal magnetorheological damper; L ef L is the spatial lever arm of the transverse magnetorheological damper; fg F is the spatial lever arm of a helical spring. m denoted as _f_, where _f is the angle between the longitudinal magnetorheological damper and the fourth swing arm; _n_, where _n_ is the angle between the spatial force Fc' and the XY plane; _m_, where _m_ is the angle between the projected component force Fd and the X-axis; _g_, where _g_ is the angle between the transverse magnetorheological damper and the third swing arm; _e_, where _e_ is the angle between the helical spring and the fifth swing arm; and _M_, where M is one-quarter of the vehicle body mass.

[0104] AB has no inherent meaning; it is a symbol used in formula simplification to simplify complex formulas.

[0105] According to formulas (18)-(20), a model was built using Simulink software. When the vehicle body acceleration is 0.3g, 0.5g, 0.8g, and 1.0g respectively, the corresponding front and rear suspension damping characteristic curves are as follows: Figure 6 , Figure 7 As shown;

[0106] See Figure 8 A method for adjusting a series variable stiffness decoupled suspension, wherein the vehicle body is equipped with a vehicle attitude sensor that can simultaneously measure the velocity, acceleration, angular velocity, and cross-acceleration in three directions: X (longitudinal), Y (lateral), and Z (vertical). The adjustment method includes the following steps:

[0107] Step S1: Determine the road conditions based on the vehicle speed and vertical acceleration, and determine the vehicle's operating status based on the pitch angular velocity;

[0108] Step S2: Power on or off the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper according to different road conditions and vehicle operating status.

[0109] Step S3: Based on the energization or de-energization status of the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper, the working state of the transverse barrel magnetorheological damper, the longitudinal barrel magnetorheological damper, the transverse torsion bar spring, the vertical torsion bar spring, the steering tie rod, and the helical spring is adjusted using a neural fuzzy parallel fusion algorithm.

[0110] In one embodiment of the present invention, step 1 is further specified as follows:

[0111] Step S11: When the vehicle speed is greater than 40 km / h or the vertical acceleration of the vehicle body is less than 0.4 m / s² 2 The road conditions were deemed good.

[0112] Step S12: When the vehicle speed is less than 40 km / h or the road surface condition is good, the vertical acceleration of the vehicle body is greater than 0.7 m / s². 2 The road conditions were deemed poor.

[0113] Step S13: When the vehicle body pitch angle is greater than 200 deg / s 2 This determines that the vehicle is in a state of rapid acceleration or braking.

[0114] Step S14: When the vehicle body roll angle acceleration is greater than 45 deg / s 2 At that time, it was determined that the vehicle was turning at high speed.

[0115] The vehicle body attitude sensor may be a nine-axis attitude sensor.

[0116] In one embodiment of the present invention, step 2 is further specifically defined as follows:

[0117] Step S21: When the road conditions are good, adjust the vehicle handling by energizing the rotary electromagnetic clutch, energizing the longitudinal barrel magnetorheological damper, and de-energizing the transverse barrel magnetorheological damper.

[0118] Step S22: When the road conditions are poor, adjust the vehicle ride comfort, de-energize the rotary electromagnetic clutch, energize the longitudinal barrel magnetorheological damper, and de-energize the transverse barrel magnetorheological damper.

[0119] Step S23: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized.

[0120] Step S24: When the vehicle is cornering at high speed, the current of the transverse barrel magnetorheological damper is cut off.

[0121] In one embodiment of the present invention, see Figure 9 Step 3 further specifies that: the suspension is identified using a neural network algorithm model. The input parameters include: road conditions, error, damping force of the lateral barrel magnetorheological damper, and damping force of the longitudinal barrel magnetorheological damper. The output parameters of the identification structure are the vehicle vertical acceleration, vehicle pitch acceleration, and vehicle roll acceleration. The damping forces of the lateral barrel magnetorheological damper and the longitudinal barrel magnetorheological damper are controlled in real time using the output parameters of the identification structure.

[0122] The error refers to the difference between the output of the suspension physical model (the actual parameters measured by sensors in the real suspension, including the vehicle's vertical acceleration, vehicle's pitch acceleration, and vehicle's roll acceleration) and the output of the neural network prediction model (vehicle's vertical acceleration, vehicle's pitch acceleration, and vehicle's roll acceleration).

[0123] The neural network is connected in parallel with the suspension model. The error between the output of the suspension model and the output of the network is used as the training signal for the network. The output of the suspension model is the actual measured output of the physical sensor. The identification result is compared with the output parameters of the suspension model. A small error indicates that the identification model has high accuracy.

[0124] Suspension model output:

[0125] y p (k+1)=f[y p (k), ..., y p (k-n+1); u(k), …u(k-m+1)]

[0126] In the above formula, y p (k+1) is the output value of the suspension physics model at time k+1, u(k) is the input value of the suspension physics model at time k, n represents the nth time, and m represents the mth time.

[0127] Network model output:

[0128]

[0129] In the above formula, y m (k+1) represents the output value of the current network model at time k+1, u(k) represents the input value of the current network model at time k, n represents the nth time, and m represents the mth time.

[0130] After a period of training, the network model can describe the suspension model quite well, that is: y m ≈y p

[0131] Integrating the above formulas yields the final network model, i.e., the neural network algorithm model, as follows:

[0132]

[0133] y p (k+1) and y m (k+1) represents the output values ​​of the suspension physical model and the neural network algorithm model at time k+1, respectively; u(k) represents the input values ​​of the suspension physical model and the neural network prediction model at time k, where n represents the nth time and m represents the mth time.

[0134] Step S31: The rotary electromagnetic clutch is de-energized, the longitudinal barrel magnetorheological damper is energized, the transverse barrel magnetorheological damper is de-energized, the helical spring works, the longitudinal barrel magnetorheological damper works actively, and the torsion bar spring does not work.

[0135] Step S32: The rotary electromagnetic clutch is energized, the longitudinal barrel magnetorheological damper is energized, the transverse barrel magnetorheological damper is de-energized, the vertical torsion bar spring is working, the longitudinal barrel magnetorheological damper is working, and the transverse torsion bar spring and helical spring are not working.

[0136] Step S33: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized and the transverse barrel magnetorheological damper works.

[0137] Step S34: When the vehicle is cornering at high speed, the current of the lateral barrel magnetorheological damper is cut off, the lateral torsion bar spring is activated, and the lateral barrel magnetorheological damper is passively activated.

[0138] The output of the suspension model is the actual measured output of the physical sensors. The identification result is compared with the output parameters of the suspension model. The small error indicates that the identification model has high accuracy.

[0139] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A series variable stiffness decoupled suspension, characterized in that, It includes a pair of shock absorber brackets, each including a vertical torsion bar spring. The vertical torsion bar spring is hinged to the chassis of the vehicle via a deep groove ball bearing. A rotating sleeve is fitted at the bottom end of the vertical torsion bar spring, and a first swing arm, a second swing arm, a third swing arm, and a fourth swing arm extend outward from the upper end of the rotating sleeve. A tie rod is hinged to the end of the first swing arm, and a control arm is hinged to the other end of the tie rod. A steering tie rod is hinged to the control arm. The second swing arm has a connecting rod hinged to the front side. One end of a transverse torsion bar spring is hinged to the connecting rod of one shock absorber bracket, and the other end of the connecting rod of the other shock absorber bracket is hinged to the other end of the transverse torsion bar spring. A transverse magnetorheological damper is hinged between the shock-absorbing supports, and the two ends of the transverse magnetorheological damper are respectively hinged to the third swing arm of the two shock-absorbing supports. The fourth swing arm is hinged to a longitudinal barrel-type magnetorheological damper at its end. The top of the vertical torsion bar spring is hinged with a spring support structure; The spring support structure includes a rotary electromagnetic clutch hinged to the top of a vertical torsion bar spring. A rotary sleeve is fitted on the outer shell of the rotary electromagnetic clutch. A fifth swing arm extends outward from the rotary sleeve, and a helical spring is hinged to the end of the fifth swing arm. The control arm has an upper control arm and a lower control arm. The tie rod is hinged to the upper control arm. The upper control arm and the lower control arm are both a pair of horizontal arms and are fixed to a steering knuckle. The pair of horizontal arms are A-shaped. The steering tie rod is hinged to the steering knuckle. The steering knuckle is connected to the wheel.

2. A stiffness matching method for a series variable stiffness decoupled suspension as described in claim 1, characterized in that, The series variable stiffness decoupled suspension has a suspension force transmission model. Based on the suspension force transmission model, the spring stiffness algorithm of the series variable stiffness decoupled suspension under static load equilibrium is obtained, and the spring stiffness under static load equilibrium condition is obtained based on the spring stiffness algorithm.

3. The stiffness matching method for a series variable stiffness decoupled suspension according to claim 2, characterized in that, The spring stiffness algorithm is as follows: ； Where K is the spring stiffness; x is the spring installation stroke; g is the gravitational acceleration; a is the angle between the steering kingpin and the XZ plane; d is the angle between the upper control arm and the XY plane; n is the angle between the spatial force Fc' and the XY plane; m is the angle between the projected component force Fd and the X-axis; e is the angle between the helical spring and the fifth swing arm; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; ad L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de L is the spatial lever arm of the longitudinal magnetorheological damper; ef L is the spatial lever arm of the transverse magnetorheological damper; fg M is the spatial lever arm of the helical spring; M is one-quarter of the vehicle body mass.

4. A damping matching method for a series variable stiffness decoupled suspension as described in claim 1, characterized in that, The series variable stiffness decoupled suspension has a suspension force transmission model. The viscous damping coefficient formula is obtained based on the suspension force transmission model. The viscous damping coefficient is obtained based on the viscous damping coefficient formula. The parameters of the series variable stiffness decoupled suspension are obtained based on the viscous damping coefficient.

5. The damping matching method for a series variable stiffness decoupled suspension according to claim 4, characterized in that, The formula for the viscous damping coefficient is as follows: ； ； ； in, This is the acceleration of the vehicle body in the Z-axis direction; M1 is the velocity of the vehicle body in the Z-axis direction; M1 is the mass of the vertical torsion bar spring; L ac L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the outer point of the upper control arm; ad L is the projected length on the Y-axis between the connection point of the pull rod and the upper control arm and the inner point of the upper control arm; be L is the spatial lever arm of the tie rod; de L is the spatial lever arm of the longitudinal magnetorheological damper; ef L is the spatial lever arm of the transverse magnetorheological damper; fg F is the spatial lever arm of the helical spring. m denoted as , where is the spring force; f is the angle between the longitudinal magnetorheological damper and the fourth swing arm; n is the angle between the spatial force Fc' and the XY plane; m is the angle between the projected component force Fd and the X-axis; g is the angle between the transverse magnetorheological damper and the third swing arm; e is the angle between the helical spring and the fifth swing arm; and M is one-quarter of the vehicle body mass.

6. A method for adjusting a series variable stiffness decoupled suspension as described in claim 1, characterized in that: The vehicle is equipped with a body attitude sensor, which can simultaneously measure the velocity, acceleration, angular velocity, and cross-acceleration in three directions: longitudinal, lateral, and vertical. The adjustment method includes the following steps: Step S1: Determine the road conditions based on the vehicle's longitudinal speed and vertical acceleration, and determine the vehicle's operating status based on the pitch angular velocity; Step S2: Power on or off the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper according to different road conditions and vehicle operating status. Step S3: Based on the energization or de-energization status of the rotary electromagnetic clutch, the transverse barrel magnetorheological damper, and the longitudinal barrel magnetorheological damper, the working state of the transverse barrel magnetorheological damper, the longitudinal barrel magnetorheological damper, the transverse torsion bar spring, the vertical torsion bar spring, the steering tie rod, and the helical spring is adjusted using a neural fuzzy parallel fusion algorithm.

7. The adjustment method for a series variable stiffness decoupled suspension according to claim 6, characterized in that: Step 1 is further specified as follows: Step S11: When the vehicle speed is greater than 40 km / h or the vertical acceleration of the vehicle body is less than 0.4 m / s² 2 The road conditions were deemed good. Step S12: When the vehicle speed is less than 40 km / h or the road surface condition is good, the vertical acceleration of the vehicle body is greater than 0.7 m / s². 2 The road conditions were deemed poor. Step S13: When the vehicle body pitch angle is greater than 200 deg / s 2 This determines that the vehicle is in a state of rapid acceleration or braking. Step S14: When the vehicle body roll angle acceleration is greater than 45 deg / s 2 At that time, it was determined that the vehicle was turning at high speed.

8. The adjustment method for a series variable stiffness decoupled suspension according to claim 7, characterized in that: Step 2 is further specified as follows: Step S21: When the road conditions are good, adjust the vehicle handling by energizing the rotary electromagnetic clutch, energizing the longitudinal barrel magnetorheological damper, and de-energizing the transverse barrel magnetorheological damper. Step S22: When the road conditions are poor, adjust the vehicle ride comfort, de-energize the rotary electromagnetic clutch, energize the longitudinal barrel magnetorheological damper, and de-energize the transverse barrel magnetorheological damper. Step S23: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized. Step S24: When the vehicle is cornering at high speed, the current of the transverse barrel magnetorheological damper is cut off.

9. The adjustment method for a series variable stiffness decoupled suspension according to claim 8, characterized in that: Step 3 further specifies the following: The suspension is identified using a neural network algorithm model. Input parameters include: road conditions, error, damping force of the lateral barrel magnetorheological damper, and damping force of the longitudinal barrel magnetorheological damper. The output parameters of the identification structure are the vehicle's vertical acceleration, vehicle pitch acceleration, and vehicle roll acceleration. The damping forces of the lateral and longitudinal barrel magnetorheological dampers are controlled in real time using these output parameters. The neural network algorithm model is as follows: ； y p (k+1) and y m (k+1) represents the output value of the suspension physical model and the neural network prediction model at time k+1; u(k) represents the input value of the suspension physical model and the neural network prediction model at time k, n represents the nth time, and m represents the mth time; Step S31: The rotary electromagnetic clutch is de-energized, the longitudinal barrel magnetorheological damper is de-energized, the transverse barrel magnetorheological damper is de-energized, the helical spring works, the longitudinal barrel magnetorheological damper works actively, and the torsion bar spring does not work. Step S32: The rotary electromagnetic clutch is energized, the longitudinal barrel magnetorheological damper is energized, the transverse barrel magnetorheological damper is de-energized, the vertical torsion bar spring is working, the longitudinal barrel magnetorheological damper is working, and the transverse torsion bar spring and helical spring are not working. Step S33: When the vehicle is in a state of rapid acceleration or braking, the transverse barrel magnetorheological damper is energized and the transverse barrel magnetorheological damper works. Step S34: When the vehicle is cornering at high speed, the current of the lateral barrel magnetorheological damper is cut off, the lateral torsion bar spring is activated, and the lateral barrel magnetorheological damper is passively activated.

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